[PATCH] Driver core: allow struct device to have a dev_t (23681e47) · Commits · 戴 / test

drivers/base/class.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -142,6 +142,7 @@ int class_register(struct class * cls)
		pr_debug("device class '%s': registering\n", cls->name);

		INIT_LIST_HEAD(&cls->children);
		INIT_LIST_HEAD(&cls->devices);
		INIT_LIST_HEAD(&cls->interfaces);
		init_MUTEX(&cls->sem);
		error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);

drivers/base/core.c

+161 −1

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#include <linux/module.h>
		#include <linux/slab.h>
		#include <linux/string.h>
		#include <linux/kdev_t.h>

		#include <asm/semaphore.h>

		@@ -98,6 +99,8 @@ static int dev_uevent_filter(struct kset kset, struct kobject kobj)
		struct device *dev = to_dev(kobj);
		if (dev->bus)
		return 1;
		if (dev->class)
		return 1;
		}
		return 0;
		}
		@@ -106,7 +109,11 @@ static const char dev_uevent_name(struct kset kset, struct kobject *kobj)
		{
		struct device *dev = to_dev(kobj);

		if (dev->bus)
		return dev->bus->name;
		if (dev->class)
		return dev->class->name;
		return NULL;
		}

		static int dev_uevent(struct kset kset, struct kobject kobj, char **envp,
		@@ -117,6 +124,16 @@ static int dev_uevent(struct kset kset, struct kobject kobj, char **envp,
		int length = 0;
		int retval = 0;

		/* add the major/minor if present */
		if (MAJOR(dev->devt)) {
		add_uevent_var(envp, num_envp, &i,
		buffer, buffer_size, &length,
		"MAJOR=%u", MAJOR(dev->devt));
		add_uevent_var(envp, num_envp, &i,
		buffer, buffer_size, &length,
		"MINOR=%u", MINOR(dev->devt));
		}

		/* add bus name of physical device */
		if (dev->bus)
		add_uevent_var(envp, num_envp, &i,
		@@ -161,6 +178,12 @@ static ssize_t store_uevent(struct device dev, struct device_attribute attr,
		return count;
		}

		static ssize_t show_dev(struct device dev, struct device_attribute attr,
		char *buf)
		{
		return print_dev_t(buf, dev->devt);
		}

		/*
		* devices_subsys - structure to be registered with kobject core.
		*/
		@@ -231,6 +254,7 @@ void device_initialize(struct device *dev)
		klist_init(&dev->klist_children, klist_children_get,
		klist_children_put);
		INIT_LIST_HEAD(&dev->dma_pools);
		INIT_LIST_HEAD(&dev->node);
		init_MUTEX(&dev->sem);
		device_init_wakeup(dev, 0);
		}
		@@ -274,6 +298,31 @@ int device_add(struct device *dev)
		dev->uevent_attr.store = store_uevent;
		device_create_file(dev, &dev->uevent_attr);

		if (MAJOR(dev->devt)) {
		struct device_attribute *attr;
		attr = kzalloc(sizeof(*attr), GFP_KERNEL);
		if (!attr) {
		error = -ENOMEM;
		goto PMError;
		}
		attr->attr.name = "dev";
		attr->attr.mode = S_IRUGO;
		if (dev->driver)
		attr->attr.owner = dev->driver->owner;
		attr->show = show_dev;
		error = device_create_file(dev, attr);
		if (error) {
		kfree(attr);
		goto attrError;
		}

		dev->devt_attr = attr;
		}

		if (dev->class)
		sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
		dev->bus_id);

		if ((error = device_pm_add(dev)))
		goto PMError;
		if ((error = bus_add_device(dev)))
		@@ -292,6 +341,11 @@ int device_add(struct device *dev)
		BusError:
		device_pm_remove(dev);
		PMError:
		if (dev->devt_attr) {
		device_remove_file(dev, dev->devt_attr);
		kfree(dev->devt_attr);
		}
		attrError:
		kobject_uevent(&dev->kobj, KOBJ_REMOVE);
		kobject_del(&dev->kobj);
		Error:
		@@ -366,6 +420,10 @@ void device_del(struct device * dev)

		if (parent)
		klist_del(&dev->knode_parent);
		if (dev->devt_attr)
		device_remove_file(dev, dev->devt_attr);
		if (dev->class)
		sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id);
		device_remove_file(dev, &dev->uevent_attr);

		/* Notify the platform of the removal, in case they
		@@ -450,3 +508,105 @@ EXPORT_SYMBOL_GPL(put_device);

		EXPORT_SYMBOL_GPL(device_create_file);
		EXPORT_SYMBOL_GPL(device_remove_file);


		static void device_create_release(struct device *dev)
		{
		pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
		kfree(dev);
		}

		/**
		* device_create - creates a device and registers it with sysfs
		* @cs: pointer to the struct class that this device should be registered to.
		* @parent: pointer to the parent struct device of this new device, if any.
		* @dev: the dev_t for the char device to be added.
		* @fmt: string for the class device's name
		*
		* This function can be used by char device classes. A struct
		* device will be created in sysfs, registered to the specified
		* class.
		* A "dev" file will be created, showing the dev_t for the device, if
		* the dev_t is not 0,0.
		* If a pointer to a parent struct device is passed in, the newly
		* created struct device will be a child of that device in sysfs. The
		* pointer to the struct device will be returned from the call. Any
		* further sysfs files that might be required can be created using this
		* pointer.
		*
		* Note: the struct class passed to this function must have previously
		* been created with a call to class_create().
		*/
		struct device device_create(struct class class, struct device *parent,
		dev_t devt, char *fmt, ...)
		{
		va_list args;
		struct device *dev = NULL;
		int retval = -ENODEV;

		if (class == NULL \|\| IS_ERR(class))
		goto error;
		if (parent == NULL) {
		printk(KERN_WARNING "%s does not work yet for NULL parents\n", __FUNCTION__);
		goto error;
		}

		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
		if (!dev) {
		retval = -ENOMEM;
		goto error;
		}

		dev->devt = devt;
		dev->class = class;
		dev->parent = parent;
		dev->release = device_create_release;

		va_start(args, fmt);
		vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
		va_end(args);
		retval = device_register(dev);
		if (retval)
		goto error;

		/* tie the class to the device */
		down(&class->sem);
		list_add_tail(&dev->node, &class->devices);
		up(&class->sem);

		return dev;

		error:
		kfree(dev);
		return ERR_PTR(retval);
		}
		EXPORT_SYMBOL_GPL(device_create);

		/**
		* device_destroy - removes a device that was created with device_create()
		* @class: the pointer to the struct class that this device was registered * with.
		* @dev: the dev_t of the device that was previously registered.
		*
		* This call unregisters and cleans up a class device that was created with a
		* call to class_device_create()
		*/
		void device_destroy(struct class *class, dev_t devt)
		{
		struct device *dev = NULL;
		struct device *dev_tmp;

		down(&class->sem);
		list_for_each_entry(dev_tmp, &class->devices, node) {
		if (dev_tmp->devt == devt) {
		dev = dev_tmp;
		break;
		}
		}
		up(&class->sem);

		if (dev) {
		list_del_init(&dev->node);
		device_unregister(dev);
		}
		}
		EXPORT_SYMBOL_GPL(device_destroy);

include/linux/device.h

+14 −0

Original line number	Diff line number	Diff line
		@@ -142,6 +142,7 @@ struct class {

		struct subsystem subsys;
		struct list_head children;
		struct list_head devices;
		struct list_head interfaces;
		struct semaphore sem; /* locks both the children and interfaces lists */

		@@ -305,6 +306,7 @@ struct device {
		struct kobject kobj;
		char bus_id[BUS_ID_SIZE]; /* position on parent bus */
		struct device_attribute uevent_attr;
		struct device_attribute *devt_attr;

		struct semaphore sem; /* semaphore to synchronize calls to
		* its driver.
		@@ -332,6 +334,11 @@ struct device {
		struct dma_coherent_mem dma_mem; / internal for coherent mem
		override */

		/* class_device migration path */
		struct list_head node;
		struct class class; / optional*/
		dev_t devt; /* dev_t, creates the sysfs "dev" */

		void (release)(struct device dev);
		};

		@@ -373,6 +380,13 @@ extern int device_attach(struct device * dev);
		extern void driver_attach(struct device_driver * drv);
		extern void device_reprobe(struct device *dev);

		/*
		* Easy functions for dynamically creating devices on the fly
		*/
		extern struct device device_create(struct class cls, struct device *parent,
		dev_t devt, char *fmt, ...)
		__attribute__((format(printf,4,5)));
		extern void device_destroy(struct class *cls, dev_t devt);

		/*
		* Platform "fixup" functions - allow the platform to have their say

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